WO2013094585A1

WO2013094585A1 - Glass fiber composite resin substrate

Info

Publication number: WO2013094585A1
Application number: PCT/JP2012/082744
Authority: WO
Inventors: 正敏湯浅; 悠子村上
Original assignee: 新日鐵住金化学株式会社
Priority date: 2011-12-22
Filing date: 2012-12-18
Publication date: 2013-06-27
Also published as: KR20140105575A; CN104011118A; TW201339247A; JP2013129766A

Abstract

A glass fiber composite resin substrate comprising a curable resin composition and glass fibers, wherein the curable resin composition contains (A) a cage-type silsesquioxane resin having at least one functional group selected from the group consisting of (meth)acryloyol groups, glycidyl groups, and vinyl groups, (B) an unsaturated compound other than the aforementioned cage-type silsesquioxane resin, having two or more unsaturated functional groups selected from the group consisting of functional groups represented by the following general formulas (1) and (2): -R¹-CR²=CH₂ (1) -CR²=CH₂ (2) [In formula (1), R¹ represents a functional group selected from the group consisting of alkylene groups, alkylidene groups, and -OCO- groups, and in formulas (1) and (2), R² independently represent a hydrogen atom or an alkyl group.], and (C) a curing catalyst, the amount of the cage-type silsesquioxane resin (A) being 5 to 90 mass % with respect to the total amount of the curable resin composition.

Description

Glass fiber composite resin substrate

The present invention relates to a glass fiber composite resin substrate.

Glass has the characteristics of excellent transparency, heat resistance, low thermal expansion, chemical stability, etc., and has been widely used as optical glass for lenses, optical disks, display substrates, etc. and contributes to industrial development. is doing. In recent years, with the reduction in weight of various optical devices, it has been studied to reduce the thickness and weight of optical glass having a large specific gravity. However, glass has a drawback that it is vulnerable to impact and easily breaks, and its mechanical strength is further reduced when it is made thinner, so that the yield due to cracking during the manufacturing process is lowered.

Therefore, as a thin film substrate that is excellent in flexibility and heat resistance and improves the ease of cracking, for example, Japanese Patent Application Laid-Open No. 2004-50565 (Patent Document 1) discloses a metal oxide polymer containing an organic group. A thin film sheet-like substrate is described in which a resin layer containing as a main component is laminated on the surface of a glass substrate. However, since such a thin sheet-like substrate uses plate-like glass, further weight reduction is difficult, and mechanical strength is still insufficient.

In recent years, transparent plastics have attracted attention as optical members that can replace glass, from the viewpoint of easy weight reduction and thinning, and excellent workability. Examples of such transparent plastics include polymethyl methacrylate (PMMA), alicyclic polyolefin, epoxy resin, silicone resin, etc. Among them, PMMA and alicyclic polyolefin have particularly excellent transparency, and thus organic glass. It is often used for applications such as optical lenses, light guide plates for liquid crystal displays, and optical disks. However, for example, when forming a low resistance transparent electrode on a flexible substrate or forming an active element such as a TFT, a temperature of at least 300 ° C. to 350 ° C. is required, whereas a resin such as PMMA is used. Is difficult to adopt as a flexible substrate because it has lower heat resistance than glass. Furthermore, since the material made of such a resin has a large coefficient of linear expansion, there is a large difference from the coefficient of linear expansion in element materials such as transparent electrodes and TFTs, resulting in problems such as cracks and disconnections. Was.

Therefore, as a method for improving the heat resistance and linear expansion coefficient of the material, a method of combining a resin and glass fiber has been developed. For example, in Japanese Patent Application Laid-Open No. 2004-231934 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2004-51960 (Patent Document 3), a glass fiber such as a glass cloth and an Abbe number and a refractive index are respectively described in A composite resin obtained by combining a curable resin such as a near epoxy resin or an acrylate resin is described.

JP 2004-50565 A JP 2004-231934 A JP 2004-51960 A

However, in the composite resins as described in Patent Documents 2 and 3, although the heat resistance to heat up to about 250 ° C. is slightly improved, the glass transition temperature is less than 300 ° C. When a conventional composite resin substrate is heated at a temperature higher than the glass transition temperature, its elastic modulus decreases and the substrate expands and deforms. The present inventors have found that it is still difficult.

The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and a sufficiently low thermal expansion coefficient. And

As a result of intensive studies to achieve the above object, the present inventors have made a (meth) acryloyl group as the curable resin composition in a glass fiber composite resin substrate comprising a curable resin composition and glass fibers. , A specific cage silsesquioxane resin having at least one group selected from the group consisting of glycidyl group and vinyl group, and two or more unsaturated functional groups containing a carbon-carbon double bond By using a curable resin composition containing a specific unsaturated compound having a curing catalyst and a content of the cage silsesquioxane resin within a specific range, a high level of heat resistance The present invention has been completed by finding that a glass fiber composite resin substrate having good properties and transparency and having a sufficiently small thermal expansion coefficient can be obtained.

That is, the glass fiber composite resin substrate of the present invention is
A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,
The curable resin composition is
(A) a cage silsesquioxane resin having at least one group selected from the group consisting of (meth) acryloyl group, glycidyl group and vinyl group,
(B) The following general formulas (1) to (2):
-R ¹ -CR ² = CH ₂ (1)
-CR ² = CH ₂ (2)
[In Formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group, and —OCO— group. In Formulas (1) to (2), R ² is independently A hydrogen atom or an alkyl group is shown. ]
An unsaturated compound other than the above cage-type silsesquioxane resin, having two or more unsaturated functional groups selected from the group consisting of the groups represented by: and (C) a curing catalyst, and (A) The content of the cage silsesquioxane resin is 5 to 90% by mass with respect to the entire curable resin composition.

As the glass fiber composite resin substrate of the present invention, the (A) cage silsesquioxane resin is represented by the following general formula (3):
[R ³ SiO _3/2 ] _n [R ⁴ SiO _3/2 ] _m ·· (3)
{In Formula (3), R ³ represents an organic group having a group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group, and R ⁴ represents a hydrogen atom, having 1 to 20 carbon atoms. Any one selected from the group consisting of a hydrocarbon group, an alkoxy group having 1 to 20 carbon atoms and an alkylsiloxy group having 1 to 20 carbon atoms, wherein n and m are the following formulas (i) to (iii):
n ≧ 1 (i)
m ≧ 0 (ii)
n + m = h (iii)
[In the formula (iii), h represents an integer selected from the group consisting of 8, 10, 12, and 14. ]
In the case where n and m are each 2 or more, R ³ and R ⁴ may be the same or different. }
It is preferable that it is a cage type silsesquioxane resin represented by these.

In the glass fiber composite resin substrate of the present invention, in the general formula (3), the ratio of n to m (n: m) is preferably 10: 0 to 4: 6, It is preferable that the cage silsesquioxane resin represented by the general formula (3) is 50% by mass or more based on the entire cage silsesquioxane resin (A).

Moreover, as the glass fiber composite resin substrate of the present invention, the unsaturated functional group of the unsaturated compound (B) is at least one selected from the group consisting of acryloyl group, methacryloyl group, allyl group and vinyl group. The number of the unsaturated functional groups of the unsaturated compound (B) is preferably 2 to 10 per molecule of the compound.

The glass fiber composite resin substrate of the present invention is preferably one obtained by impregnating the glass fiber with the curable resin composition and then curing the curable resin composition. Furthermore, the mass ratio of the cured product of the curable resin composition to the glass fiber (the mass of the cured product: the mass of the glass fiber) is preferably 20:80 to 70:30, and the thickness is 0.03. It is preferable that the thickness is ˜0.5 mm.

According to the present invention, it is possible to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and having a sufficiently small thermal expansion coefficient.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof. The glass fiber composite resin substrate of the present invention is
A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,
The curable resin composition is
(A) a cage silsesquioxane resin having at least one group selected from the group consisting of (meth) acryloyl group, glycidyl group and vinyl group,
(B) The cage silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of the group represented by the general formula (1) and the group represented by the general formula (2). Unsaturated compounds other than, and
(C) a curing catalyst is contained, and the content of the (A) cage silsesquioxane resin is 5 to 90% by mass with respect to the entire curable resin composition.

<(A) Basket-type silsesquioxane resin>
In the present invention, the cage-type silsesquioxane resin refers to a siloxane having a completely closed polyhedral structure or a siloxane in which a part of —Si—O—Si— bond in the polyhedral structure is cleaved. It may be an oligomer obtained by polymerizing a type silsesquioxane resin as a monomer. The cage silsesquioxane resin according to the present invention is at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group (hereinafter sometimes collectively referred to as a curable functional group). have. The curable functional group is preferably bonded directly or via a divalent organic group to a silicon atom arranged at the apex of the polyhedron of the cage silsesquioxane skeleton. Examples of the divalent organic group include an alkylene group and a phenylene group. In the present invention, the (meth) acryloyl group means a methacryloyl group and an acryloyl group.

The cage-type silsesquioxane resin according to the present invention has a cage-type silylene from the viewpoint that the crosslinking density of the curable resin composition is higher and the heat resistance of the glass fiber composite resin substrate tends to be further improved. It is preferable that the curable functional group is bonded to all the vertices of the polyhedron of the sesquioxane skeleton, and the molecular weight distribution and the molecular structure are controlled, but some of the curable functional groups are alkyl. Other groups such as a group and a phenyl group may be substituted. When a part of the curable functional group is replaced with another group, from the viewpoint of avoiding a decrease in the crosslinking density, the curable functional group in the cage silsesquioxane resin according to the present invention The molar ratio with other groups ([average number of moles of curable functional group]: [average number of moles of other groups]) is preferably 10: 0 to 6: 4. In the present invention, the ratio between the number of curable functional groups and the number of other groups in the cage silsesquioxane resin is ¹ H-NMR (device name: JNM-ECA400 (manufactured by JEOL Ltd.) , Solvent: chloroform-d, temperature: 22.7 ° C., 400 MHz), and the integration ratio of peaks of the curable functional group and other groups.

Further, as the cage silsesquioxane resin according to the present invention, since a crosslinked structure having a rigid structure is formed, the heat resistance in the obtained glass fiber composite resin substrate is further improved, and the thermal expansion coefficient is further increased. From the viewpoint of tending to decrease, the following general formula (3):
[R ³ SiO _3/2 ] _n [R ⁴ SiO _3/2 ] _m ·· (3)
It is preferable that it is the cage polysilsesquioxane resin of the closed polyhedral structure represented by these.

In the formula (3), R ³ represents an organic group having any one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group. Examples of such an organic group include a (meth) acryloyl group; a glycidyl group; a vinyl group; a (meth) acryloyl group, a glycidyl group, or a group in which a vinyl group is bonded to a divalent hydrocarbon group such as an alkylene group or a phenylene group. Is mentioned. The alkylene group may be linear or branched, has a short bond distance, and from the viewpoint that the heat resistance of the obtained glass fiber composite resin substrate tends to be further improved. The number is preferably 1 to 3. Examples of the phenylene group include an unsubstituted phenylene group and a 1,2-phenylene group having a lower alkyl group. Among these, the divalent hydrocarbon group is more preferably an alkylene group having 1 to 3 carbon atoms from the viewpoint of easy availability of raw materials, and a glass fiber composite resin substrate having a higher crosslink density. From the viewpoint of being obtained, a propylene group is more preferable.

Specific examples of R ³ include a methacryloxypropyl group, a glycidoxypropyl group, and an epoxycyclohexyl group. Among these, from the viewpoint of easy availability of raw materials and high polymerization reactivity, methacryloxy. A propyl group is preferred.

In the formula (3), R ⁴ is any selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and an alkylsiloxy group having 1 to 20 carbon atoms. Indicate. The hydrocarbon group having 1 to 20 carbon atoms may be linear, branched or cyclic, and may be an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. Examples thereof include an alkyl group, a C3-C20 cycloalkenyl group, a phenyl group, and a styryl group. The alkyl group having 1 to 20 carbon atoms may be linear or branched, and has a carbon number from the viewpoint that it is easy to obtain a cage silsesquioxane skeleton. 2 to 10 chain alkyl groups are preferred. Examples of the cycloalkyl group having 3 to 20 carbon atoms include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclohexylethyl group. Among these, from the viewpoint of easy availability. A cyclohexyl group is preferred. Examples of the cycloalkenyl group having 3 to 20 carbon atoms include a cyclopentenyl group and a cyclohexenyl group. Among these, a cyclopentenyl group is preferable from the viewpoint of easy availability. Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, and an isopropyl group. Among them, a methoxy group is preferable from the viewpoint of high reactivity. Further, examples of the alkylsiloxy group having 1 to 20 carbon atoms include trimethylsiloxy group, triethylsiloxy group, triphenylsiloxy group, dimethylsiloxy group, t-butyldimethylsiloxy group and the like. Among these, as R ⁴ , an alkyl group having 2 to 10 carbon atoms and a phenyl group are more preferable from the viewpoint of easily obtaining a cage silsesquioxane skeleton.

Further, in the above formula (3), n and m are the following formulas (i) to (iii):
n ≧ 1 (i)
m ≧ 0 (ii)
n + m = h (iii)
[In the formula (iii), h represents an integer selected from the group consisting of 8, 10, 12, and 14. ]
An integer satisfying the condition represented by When n satisfies the condition represented by the above formula (i), the cage silsesquioxane resin according to the present invention has one or more curable functional groups. Therefore, the unsaturated compound (B) according to the present invention It is possible to obtain a glass fiber composite resin substrate having a high level of heat resistance and transparency and having a sufficiently low thermal expansion coefficient by radical polymerization. In addition, when n and m satisfy the condition represented by the above formula (iii), the cage silsesquioxane resin according to the present invention has a cage structure almost completely condensed, and has a rigid structure by radical polymerization. Since a crosslinked structure is formed, a high level of heat resistance and transparency and a sufficiently small thermal expansion coefficient are achieved in the glass fiber composite resin substrate. When n and m are each 2 or more, R ³ and R ⁴ may be the same or different.

In the cage silsesquioxane resin according to the present invention, the ratio of n to m (n: m) is preferably 10: 0 to 4: 6, and 10: 0 to 5: 5. More preferably. When the number of m with respect to n exceeds the upper limit, the crosslink density of the glass fiber composite resin substrate is decreased, and the heat resistance tends to decrease or the thermal expansion coefficient tends to increase.

In the present invention, the ratio of n to m (n: m), that is, the number of curable functional groups bonded to the apex of the polyhedron of the cage silsesquioxane resin and the number of other groups The ratio can be obtained by the same method as described above.

Further, as the cage silsesquioxane resin according to the present invention, since a crosslinked structure having a rigid structure is formed, the heat resistance in the obtained glass fiber composite resin substrate is further improved, and the thermal expansion coefficient is further increased. In view of the tendency to decrease, the cage silsesquioxane resin represented by the formula (3) is preferably 50% by mass or more based on the entire cage silsesquioxane resin according to the present invention. 70% by mass or more is more preferable.

As a method for obtaining such a cage silsesquioxane resin, for example, the following general formula (4):
R ³ SiX ₃ (4)
[In the formula (4), R ³ has the same meaning as R ³ in the general formula (3), and X is any one selected from the group consisting of an alkoxy group, an acetoxy group, a halogen atom and a hydroxy group. The hydrolyzable group of is shown. ]
A silicon compound (a) represented by the following general formula (5):
R ⁴ SiX ₃ (5)
[In Formula (5), R ⁴ has the same meaning as R ⁴ in General Formula (3), and X has the same meaning as X in General Formula (4). ]
Can be obtained by hydrolyzing in the presence of water, an organic polar solvent and a basic catalyst.

In the above formulas (4) and (5), X is each independently a hydrolyzable group selected from the group consisting of an alkoxy group, an acetoxy group, a halogen atom and a hydroxy group. The hydrolyzable group is preferably an alkoxy group. Examples of the alkoxy group include methoxy group, ethoxy group, n- and i-propoxy group, n-, i- and t-butoxy group, and methoxy group is preferable from the viewpoint of high reactivity.

Examples of the silicon compound (a) include methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxy. Silane, allyltrimethoxysilane, allyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid Examples thereof include xylpropyltriethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Among these, from the viewpoint of easy availability of raw materials, the silicon compound (a) is preferably 3-methacryloxypropyltrimethoxysilane or 3-acryloxypropyltrimethoxysilane. Moreover, as said silicon compound (a), 1 type may be used independently and 2 or more types may be used in combination.

Examples of the silicon compound (b) include phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxy. Examples thereof include silane, n-butyltriethoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, n-octyltrimethoxysilane, and n-octyltriethoxysilane. Moreover, as said silicon compound (b), 1 type may be used independently and 2 or more types may be used in combination.

As a mixing ratio of the silicon compound (a) and the silicon compound (b), a mixing molar ratio (a: b) is represented by the following formula (vi):
a: b = n: m (vi)
[In formula (vi), n and m are synonymous with n and m in said formula (3). ]
It is preferable that the condition represented by

The water may be a mass that is sufficient to hydrolyze the hydrolyzable groups in the silicon compounds (a) and (b), and is calculated from the mass of the silicon compounds (a) and (b). The mass is preferably equivalent to 1.0 to 1.5 times mol of the theoretical amount (mol) of the number of hydrolyzable groups to be formed. In addition, as said water, you may use the water contained in the aqueous solution of the basic catalyst mentioned later as it is.

Examples of the organic polar solvent include alcohols such as methanol, ethanol and 2-propanol; acetone; tetrahydrofuran and the like. One of these may be used alone, or two or more may be used in combination. Among these, from the viewpoint of efficiently forming a cage silsesquioxane skeleton, lower alcohols having 1 to 6 carbon atoms that are soluble in water are preferable, and 2-propanol is more preferable. .

Examples of the basic catalyst include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, cesium hydroxide; tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyl Examples thereof include ammonium hydroxide salts such as triethylammonium hydroxide. As the basic catalyst according to the present invention, one of these may be used alone, or two or more may be used in combination. Among these, tetramethylammonium hydroxide is preferably used from the viewpoint of high catalytic activity. The amount of such a basic catalyst is preferably 0.1 to 10% by mass with respect to the total mass of the silicon compounds (a) and (b). In addition, since the said basic catalyst is normally used as aqueous solution, you may use the water contained in the aqueous solution of this basic catalyst as said water.

In the hydrolysis, the reaction time is preferably 2 hours or longer, the reaction temperature is preferably 0 to 50 ° C., and more preferably 20 to 40 ° C. When the reaction time and reaction temperature are less than the lower limit, the hydrolyzable group tends to remain in an unreacted state. On the other hand, when the reaction temperature exceeds the above upper limit, the reaction rate becomes too fast, so that a complicated condensation reaction proceeds, and as a result, an increase in the molecular weight of the hydrolysis product is promoted.

By such a method, a reaction composition containing the cage silsesquioxane resin according to the present invention can be obtained. In such a reaction composition, the cage silsesquioxane resin according to the present invention (fully condensed cage silsesquioxane resin (for example, a resin represented by the above formula (3)), partially cleaved cage type In addition to (silsesquioxane resin), a plurality of ladder-type silsesquioxane resins, random-type silsesquioxane resins, and the like are contained as reaction by-products. In such a reaction composition, as the content of the cage silsesquioxane resin according to the present invention, from the viewpoint that the reaction composition can be used as a raw material of the curable resin composition according to the present invention as it is, It is preferable that it is 50 mass% or more with respect to the said whole reaction composition. Moreover, as content of cage-type silsesquioxane resin represented by said Formula (3) among the obtained cage-type silsesquioxane resins, it is 50 mass with respect to the said whole cage-type silsesquioxane resin. % Or more, and more preferably 70% by mass or more.

In the present invention, the total content of the cage silsesquioxane resin according to the present invention in the composition and the content of the cage silsesquioxane resin represented by the formula (3) are as follows: liquid chromatography mass spectrometry (LC-MS, HPLC: Agilent 1100 Series Systems ( manufactured by Agilent Technology ^{Inc.), MS: QSTAR R XL Hybrid} LC / MS / MS System (AB SCIEX Inc.) column: SunFire C18 column, mobile phase : H ₂ O—CH ₃ CN (30-70), speed: 1 ml / min, temperature: 40 ° C., detector: UV (254 nm)) structure of a cage silsesquioxane resin and gel permeation Chromatography (Equipment name: HLC-83 It can be determined from the molecular weight (number average molecular weight) measured by 20 GPC (manufactured by Tosoh Corporation), solvent: THF, column: ultra-high-speed semi-micro SEC column SuperH series, temperature: 40 ° C., speed: 0.6 ml / min).

In the present invention, one of these cage silsesquioxane resins may be used alone or in combination of two or more.

<(B) unsaturated compound>
The unsaturated compound according to the present invention includes the following general formulas (1) to (2):
-R ¹ -CR ² = CH ₂ (1)
-CR ² = CH ₂ (2)
[In Formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group, and —OCO— group. In Formulas (1) to (2), R ² is independently A hydrogen atom or an alkyl group is shown. ]
A compound other than the above cage-type silsesquioxane resin, having two or more unsaturated functional groups selected from the group consisting of groups represented by: Moreover, the group represented by the formula (1) is excluded from the group containing the group represented by the formula (2).

In the formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group, and an —OCO— group. The alkylene group and the alkylidene group may be linear or branched, have a short bond distance, and the heat resistance of the obtained glass fiber composite resin substrate tends to be further improved. Therefore, the number of carbon atoms is preferably 1-6. Further, among these, R ¹ is preferably an —OCO— group from the viewpoint of high radical polymerization reactivity.

In formula (1) and (2), R < ² > shows a hydrogen atom or an alkyl group each independently. The alkyl group may be linear or branched, and preferably has 1 to 3 carbon atoms from the viewpoint of better radical polymerization reactivity. Such R ² is preferably a hydrogen atom or a methyl group from the viewpoint that the reactivity of radical polymerization is further improved.

Specific examples of such unsaturated functional groups include acryloyl groups, methacryloyl groups, allyl groups, and vinyl groups. Since the unsaturated compound according to the present invention has such an unsaturated functional group, it can be radically polymerized with the (A) cage-type silsesquioxane resin having the curable functional group, The glass fiber composite resin substrate of the present invention having a high level of heat resistance and transparency and a sufficiently small thermal expansion coefficient can be obtained.

The unsaturated compound according to the present invention has two or more unsaturated functional groups per molecule of the compound. When the number of the unsaturated functional groups is less than the lower limit, a sufficient cross-linked structure is not formed even by radical polymerization with the cage silsesquioxane resin. The elastic modulus is lowered and the heat resistance is lowered. Further, from the viewpoint of further improving the elastic modulus and heat resistance, the number of the unsaturated functional groups is preferably 2 to 10. The unsaturated compound according to the present invention may be a monomer or a polymer. When the unsaturated compound is a polymer, the number of unsaturated functional groups is an average value per molecule of the compound. It is. The number (or average number) of unsaturated functional groups per molecule of the compound was ¹ H-NMR (device name: JNM-ECA400 (manufactured by JEOL Ltd.), solvent: chloroform-d, temperature: 22.7. Peak area of unsaturated functional group group and gel permeation chromatography (GPC, (device name: HLC-8320GPC (manufactured by Tosoh Corporation)), solvent: THF, column: ultra-high-speed semi-micro SEC column SuperH Series, temperature: 40 ° C., speed: 0.6 ml / min) can be determined from the molecular weight (or number average molecular weight) measured.

The unsaturated compound according to the present invention is not particularly limited as long as it has two or more unsaturated functional groups per molecule of the compound, and has a molecular weight (weight average molecular weight in the case of a polymer) of 80. It is preferably ˜5000. When the molecular weight is less than the lower limit, when an unreacted unsaturated compound remains in the curing of the curable resin composition, the unreacted unsaturated compound becomes a volatile component in the heat treatment such as heat treatment, and the weight change after curing. On the other hand, when the above upper limit is exceeded, the solubility with the cage silsesquioxane resin may be reduced, or the resulting curable resin composition may have a high viscosity and be handled. It tends to be difficult.

Examples of such unsaturated compounds include dicyclopentanyl diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, bisphenol full orange acrylate, and tetraethylene glycol diacrylate. Acrylate, hydroxypivalate neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, among others, solubility in cage silsesquioxane resin From the viewpoint that the heat resistance of the obtained glass fiber composite resin substrate tends to be higher, the number of carbon atoms The compound unsaturated functional groups are bonded two or more preferably in hydrocarbon compounds and 30, dicyclopentanyl diacrylate, bisphenol fluorene diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate is more preferable. In addition, as the unsaturated compound according to the present invention, one kind may be used alone, or two or more kinds may be used in combination. <(C) Curing Catalyst>
The curing catalyst according to the present invention is a catalyst that accelerates a curing reaction (radical polymerization reaction) between the (A) cage silsesquioxane resin and the (B) unsaturated compound. Examples of such a curing catalyst include a radical polymerization initiator, and examples of the radical polymerization initiator include a photo radical polymerization initiator and a thermal radical polymerization initiator.

Examples of the photoradical polymerization initiator include acetophenone-based, benzoin-based, benzophenone-based, thioxanthone-based, and acylphosphine oxide-based photopolymerization initiators. Specific examples include trichloroacetophenone, diethoxyacetophenone, 1-phenyl- 2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, benzoin methyl ether, benzyldimethyl ketal, Examples include benzophenone, thioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenylglyoxylate, camphorquinone, benzyl, anthraquinone, Michler's ketone and the like. Examples of the thermal radical polymerization initiator include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, and peroxyester heat. A polymerization initiator is mentioned. As the curing catalyst according to the present invention, one of these may be used alone, or two or more may be used in combination, and the photo radical polymerization initiator and the thermal radical polymerization initiator are used in combination. May be.

<Curable resin composition>
The curable resin composition according to the present invention contains the (A) cage-type silsesquioxane resin, the (B) unsaturated compound, and the (C) curing catalyst.

In the curable resin composition according to the present invention, the content of the cage silsesquioxane resin needs to be 5 to 90% by mass with respect to the entire curable resin composition. When the content of the cage silsesquioxane resin is less than the lower limit, the glass transition temperature in the glass fiber composite resin substrate is lowered and the thermal expansion coefficient is increased. Become. On the other hand, when the upper limit is exceeded, the crosslink density in the cured product increases and the glass fiber composite resin substrate becomes brittle, making it difficult to handle.

In addition, from the viewpoint of further improving the heat resistance of the glass fiber composite resin substrate and further improving the strength, the content of the cage silsesquioxane resin is preferably 8 to 80% by mass. . Further, from the same viewpoint as described above, the cage silsesquioxane resin in which 50% by mass or more (more preferably 70% by mass or more) of the cage silsesquioxane resin is represented by the formula (3) Preferably, as the curable resin composition according to the present invention, the content of the cage silsesquioxane resin represented by the formula (3) is 2.5 to 2.5% with respect to the entire curable resin composition. It is preferably 90% by mass, and more preferably 5 to 80% by mass.

In the curable resin composition according to the present invention, the content of the unsaturated compound is preferably 5 to 90% by mass with respect to the entire curable resin composition, and is 10 to 70% by mass. More preferably. When the content of the unsaturated compound is less than the lower limit, the solubility of the curable resin composition is decreased or the solution viscosity is increased, so that the impregnation property to the glass fiber tends to be decreased. On the other hand, when exceeding the said upper limit, the glass transition temperature of the hardened | cured material of curable resin composition falls, and it exists in the tendency for the heat resistance of the glass fiber composite resin substrate obtained to fall.

Furthermore, in the curable resin composition according to the present invention, the content of the curing catalyst is preferably 0.1 to 5.0% by mass with respect to the entire curable resin composition, More preferably, it is -3.0 mass%. When the content of the curing catalyst is less than the lower limit, the curing reaction becomes insufficient, and the strength and rigidity of the resulting cured product tend to decrease. Coloring may occur.

Further, as the curable resin composition according to the present invention, a curable compound other than the (A) cage-type silsesquioxane resin and the (B) unsaturated compound (hereinafter sometimes referred to as a curable compound). Furthermore, you may contain. Such a curable compound is not particularly limited as long as it is a compound that can be cured by heating or irradiation with active energy rays, and has compatibility and reactivity with the cage silsesquioxane resin. A compound is preferred.

Examples of such a curable compound include a reactive oligomer which is a polymer having about 2 to 20 repeating units of a structural unit, and a reactive monomer having a low molecular weight and a low viscosity. Specific examples of the reactive oligomer include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate, polyene / thiol, silicone acrylate, polybutadiene, and polystyrylethyl methacrylate. Is mentioned. Specific examples of the reactive monomer include styrene, vinyl acetate, N-vinyl pyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, Monofunctional monomers such as cyclopentenyloxyethyl acrylate, phenoxyethyl acrylate, and trifluoroethyl methacrylate are exemplified. Such curable compounds may be used alone or in combination of two or more.

When the curable resin composition according to the present invention contains the curable compound, the content is preferably 40% by mass or less based on the entire curable resin composition. When the content of the curable compound exceeds the upper limit, it is difficult to form a sufficient crosslinked structure, and the heat resistance of the obtained glass fiber composite resin substrate tends to decrease.

Moreover, the curable resin composition according to the present invention may further contain various additives within a range not impairing the effects of the present invention. Examples of the additive include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, mold release agents, foaming agents, and nucleating agents. , Coloring agents, crosslinking agents, dispersion aids and the like. When such an additive is contained, the content is preferably 30% by mass or less with respect to the entire curable resin composition.

Furthermore, the curable resin composition according to the present invention may further contain a solvent such as methyl ethyl ketone, toluene, ethyl acetate for the purpose of adjusting its viscosity, etc., but in the solvent devolatilization step. Since it takes time, the production efficiency decreases, and the solvent may remain inside the obtained glass fiber composite resin substrate, so that the characteristics of the substrate may decrease. It is preferable that it is 5 mass% or less with respect to the whole curable resin composition, and it is more preferable that the solvent is not contained.

<Glass fiber>
Examples of the form of the glass fiber according to the present invention include a yarn-like yarn, a glass cloth, and a non-work cloth. Among these, glass cloth is preferable from the viewpoint that the effect of reducing the thermal expansion coefficient is high. Examples of the glass cloth material include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and quartz glass depending on the composition of the glass. Among these, the refractive index range is preferable. E glass, S glass, T glass, and NE glass are preferred from the viewpoint of being within the above range and being easily available.

In addition, the glass fiber according to the present invention includes a silane coupling agent and various surfactants for the purpose of improving wettability, affinity, and adhesion at the interface between the curable resin composition and the glass fiber. Cleaning with an inorganic acid; corona discharge treatment; ultraviolet irradiation treatment; a surface treated by plasma treatment or the like may be used.

Further, the refractive index of the glass fiber according to the present invention is preferably such that the difference from the refractive index of the cured product of the curable resin composition is within a range of −0.02 to +0.02. More preferably, it is within the range of 01 to +0.01. When the difference in refractive index is out of the above range, the interface scattering between the cured product of the curable resin composition and the glass fiber is increased, and the transparency of the glass fiber composite resin substrate is decreased. , It tends to be difficult to use as a glass substitute substrate for solar cells.

Further, when the glass fiber according to the present invention is a glass cloth, a non-woven cloth, etc., the thickness can be appropriately selected depending on the purpose of using the glass fiber composite resin substrate. From the viewpoint that the impregnation property to the glass fiber tends to be improved, the thickness is preferably 30 to 100 μm.

<Glass fiber composite resin substrate>
The glass fiber composite resin substrate of the present invention is a composite of the curable resin composition and the glass fiber. A method for producing such a glass fiber composite resin substrate is not particularly limited, and examples thereof include a method of curing the curable resin composition after impregnating the glass fiber with the curable resin composition. .

In such a method, first, the (A) cage silsesquioxane resin, the (B) unsaturated compound, the (C) curing catalyst, and, if necessary, other compounds and solvents, etc. at room temperature ( 20 to 25 ° C.) to obtain a curable resin composition according to the present invention. Next, the curable resin composition is impregnated into the glass fiber by a method such as dropping or dipping, and the solvent is removed as necessary. Next, the glass fiber impregnated with the curable resin composition is subjected to heat treatment and / or active energy ray irradiation treatment to cure the curable resin composition, and the glass fiber composite resin substrate of the present invention is obtained. obtain.

As the glass fiber composite resin substrate of the present invention, the mass ratio of the cured product of the curable resin composition to the glass fiber per 1 m ² (mass of cured product: mass of glass fiber) is 20:80 to 70. : 30 is preferable, and 40:60 to 60:40 is more preferable. When the ratio of the glass fiber to the cured product is less than the lower limit, the heat resistance of the glass fiber composite resin substrate is lowered and the thermal expansion coefficient tends to exceed 20 ppm / K, and on the other hand, exceeds the upper limit. In such a case, impregnation into the glass fibers becomes insufficient, and voids remain between the fibers, so that the transparency of the glass fiber composite resin substrate tends to decrease (increased haze). Therefore, in the impregnation, it is preferable to impregnate so that the ratio of the mass of the curable resin composition after curing and the mass of the glass fiber is within the above range.

Furthermore, the impregnation can be adjusted as appropriate depending on the type of glass fiber and the purpose of using the glass fiber composite resin substrate, but the thickness and production of liquid crystal displays and organic EL displays to which the glass fiber composite resin substrate is applied. From the viewpoint of compatibility with the process (roll to roll), it is preferable to impregnate the obtained glass fiber composite resin substrate so as to have a thickness of 0.03 to 0.5 mm, preferably 0.05 to 0.2 mm.

The heating temperature in the heat treatment can be appropriately adjusted according to the curable resin composition, but is preferably 50 to 200 ° C, more preferably 80 to 180 ° C. If the heating temperature is less than the lower limit, the curing reaction is not sufficiently progressed and a sufficient cross-linked structure tends not to be formed. On the other hand, if the heating temperature exceeds the upper limit, the curable resin composition is deteriorated or volatilized before being cured. There is a tendency for problems to occur. Further, the heating time in the heat treatment varies depending on the heating temperature and the curable resin composition, and thus cannot be generally described, but is preferably 30 to 60 minutes. In addition, as the heat treatment, it is possible to suppress the inhibition of the radical polymerization reaction of the curable resin composition due to oxygen, and from the viewpoint that a more sufficient cross-linked structure tends to be formed, nitrogen or the like is not used. It is preferable to carry out in an active gas atmosphere.

Further, as the active energy ray irradiation conditions in the active energy ray irradiation treatment, it is preferable to irradiate ultraviolet rays having a wavelength of 10 to 400 nm and visible rays having a wavelength of 400 to 700 nm, and to irradiate near ultraviolet rays having a wavelength of 200 to 400 nm. Is more preferable. The integrated exposure amount is preferably 2000 to 10,000 mJ / cm ² . As a source of the active energy ray, a low-pressure mercury lamp (output: 0.4 to 4 W / cm), a high-pressure mercury lamp (40 to 160 W / cm), an ultra-high pressure mercury lamp (173 to 435 W / cm), a metal halide lamp (80 to 160 W / cm), pulse xenon lamp (80 to 120 W / cm), electrodeless discharge lamp (80 to 120 W / cm), and the like.

The glass fiber composite resin substrate of the present invention may further include a coating layer made of a resin on one surface or both surfaces of the glass fiber composite resin substrate for the purpose of smoothing the surface. good. The resin preferably has heat resistance, transparency, and chemical resistance, and it is particularly preferable to use the curable resin composition according to the present invention. The glass fiber composite resin substrate of the present invention may further include a gas barrier layer against oxygen and water vapor as necessary.

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. In each of the preparation examples, examples, and comparative examples, the refractive index measurement, the total light transmittance measurement, and the heat resistance evaluation were performed by the following methods.

(Refractive index measurement)
The curable resin composition obtained in each preparation example was cast (cast) to a thickness of 0.1 mm using a roll coater, and 2000 mJ / cm ² using an 80 W / cm high-pressure mercury lamp. A sheet-like cured product was obtained by curing with the accumulated exposure amount. The obtained cured product was measured for the refractive index at 589 nm using a refractometer (DR-M2, manufactured by Atago Co., Ltd.).

(Total light transmittance measurement)
About the glass fiber composite resin substrate obtained in each Example and the comparative example, the total light transmittance (%) was measured using the haze meter (NDH2000, Nippon Denshoku).

(Heat resistance evaluation)
Glass transition temperature measurement, dynamic viscoelasticity reduction rate measurement About the glass fiber composite resin substrate obtained in each Example and Comparative Example, a dynamic viscoelasticity measuring apparatus (trade name: DVE-V4, manufacturer: UBM) The dynamic viscoelasticity measurement is performed in the temperature range of 30 to 300 ° C under the condition of the temperature rising rate of 5 ° C / min., And the Tanδ peak temperature in the temperature range of 30 to 300 ° C is the glass transition. The temperature (Tg (° C.)) was used. The dynamic viscoelasticity reduction rate (ΔE ′ (%)) is expressed by the following formula:
ΔE ′ (%) = (E ′ ₃₀ −E ′ ₃₀₀ ) / E ′ ₃₀
[In the formula, E ′ ₃₀ indicates dynamic viscoelasticity at 30 ° C., and E ′ ₃₀₀ indicates dynamic viscoelasticity at 300 ° C.]
Determined by In addition, it shows that the heat resistance of a glass fiber composite resin board | substrate is so high that a glass transition temperature is high and / or a dynamic viscoelastic fall rate is small.

-Thermal expansion coefficient (linear thermal expansion coefficient) measurement About the glass fiber composite resin substrate obtained in each Example and the comparative example, the thermomechanical analyzer (TMA, brand name: TMA4000SA, manufacture company name: BRUKER company make) was used. The elongation in the plane direction (X direction) of the glass fiber composite resin substrate (thickness 0.1 mm) in the temperature range of 30 to 200 ° C. under the conditions of a temperature rising rate of 5 ° C./min and a compressive load of 0.1 N. The average value was determined, and the thermal expansion coefficient (ppm / K) in the surface direction (X direction) of the glass fiber composite resin substrate was determined from this value. In addition, it shows that the heat resistance of a glass fiber composite resin substrate is so high that a thermal expansion coefficient is small.

(Synthesis example 1: basket type silsesquioxane resin (I))
The cage silsesquioxane resin (I) was produced according to the method described in JP-A No. 2004-143449. First, a reaction vessel equipped with a stirrer, a dropping funnel, and a thermometer was charged with 40 ml of 2-propanol (IPA) as a solvent and 3.1 g of 5% tetramethylammonium hydroxide aqueous solution (TMAH aqueous solution) as a basic catalyst. I entered. An addition funnel was charged with 15 ml of IPA and 12.7 g of 3-methacryloxypropyltrimethoxysilane to prepare an IPA solution of 3-methacryloxypropyltrimethoxysilane, which was stirred in the reaction vessel at room temperature. The solution was added dropwise over 30 minutes. After completion of dropping, the mixture was further stirred for 2 hours without heating. After stirring, IPA was removed under reduced pressure to obtain 7.5 g of a composition containing a cage silsesquioxane resin (I). In the obtained composition, the cage-type silsesquioxane resin (I) according to the present invention is 97% by mass with respect to the entire composition, of which the cage-type silsesquioxane represented by the formula (3) The sun resin is 90% by mass with respect to the entire cage silsesquioxane resin (I). As a result of mass spectrometry after liquid chromatographic separation, n in the formula (3) is 8, 10, 12. there were.

(Synthesis example 2: basket type silsesquioxane resin (II))
A dropping funnel was charged with 15 ml of IPA, 7.2 g of 3-methacryloxypropyltrimethoxysilane and 5.7 g of phenyltrimethoxysilane to prepare an IPA solution of 3-methacryloxypropyltrimethoxysilane and phenyltrimethoxysilane, 8.7 g of a composition containing a cage-type silsesquioxane resin (II) was obtained in the same manner as in Synthesis Example 1 except that this was used in place of the IPA solution of 3-methacryloxypropyltrimethoxysilane. In the obtained composition, the cage-type silsesquioxane resin (II) according to the present invention is 96% by mass with respect to the whole composition, of which the cage-type silsesquioxane represented by the formula (3) The sun resin is 92% by mass with respect to the entire cage silsesquioxane resin (II). As a result of mass spectrometry after liquid chromatographic separation, n + m in the formula (3) is 8, 10, and 12. there were. Moreover, n: m was 4: 4.

(Preparation Example 1: Curable resin composition (I))
Cage-type silsesquioxane resin (I) obtained in Synthesis Example 1: 60 parts by mass (converted to cage-type silsesquioxane resin), trimethylolpropane triacrylate: 25 parts by mass, dicyclopentanyl diacrylate: 15 parts by mass and 1-hydroxycyclohexyl phenyl ketone: 2.5 parts by mass as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (I). When refractive index measurement was performed for this curable resin composition (I), the refractive index was 1.529, and it was confirmed that a transparent cured product was obtained. The composition of the resulting curable resin composition (I) is shown in Table 1.

(Preparation Example 2: Curable resin composition (II))
Cage-type silsesquioxane resin (I) obtained in Synthesis Example 1: 30 parts by mass (converted to cage-type silsesquioxane resin), dicyclopentanyl diacrylate: 35 parts by mass, pentaerythritol tetraacrylate: 35 A liquid curable resin composition (II) was obtained by mixing 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator. When refractive index measurement was performed for this curable resin composition (II), the refractive index was 1.531, and it was confirmed that a transparent cured product was obtained. The composition of the resulting curable resin composition (II) is shown in Table 1.

(Preparation Example 3: Curable resin composition (III))
Cage-type silsesquioxane resin (I) obtained in Synthesis Example 1: 10 parts by mass (converted to cage-type silsesquioxane resin), trimethylolpropane triacrylate: 65 parts by mass, dicyclopentanyl diacrylate: 35 parts by mass and 1-hydroxycyclohexyl phenyl ketone: 2.5 parts by mass as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (III). When refractive index measurement was performed for this curable resin composition (III), the refractive index was 1.531, and it was confirmed that a transparent cured product was obtained. The composition of the obtained curable resin composition (III) is shown in Table 1.

(Preparation Example 4: Curable resin composition (IV))
Cage-type silsesquioxane resin (II) obtained in Synthesis Example 2: 15 parts by mass (converted to cage-type silsesquioxane resin), trimethylolpropane triacrylate: 50 parts by mass, bisphenol full orange acrylate: 35 parts by mass And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (IV). When refractive index measurement was performed for this curable resin composition (IV), the refractive index was 1.558, and it was confirmed that a transparent cured product was obtained. The composition of the obtained curable resin composition (IV) is shown in Table 1.

(Preparation Example 5: Curable resin composition (V))
Cage-type silsesquioxane resin (II) obtained in Synthesis Example 2: 35 parts by mass (converted to cage-type silsesquioxane resin), pentaerythritol tetraacrylate: 25 parts by mass, bisphenol fluorenediacrylate acrylate: 40 parts by mass And 1-hydroxycyclohexyl phenyl ketone: 2.5 parts by mass as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (V). When refractive index measurement was performed for this curable resin composition (V), the refractive index was 1.560, and it was confirmed that a transparent cured product was obtained. The composition of the obtained curable resin composition (V) is shown in Table 1.

(Preparation Example 6: Curable resin composition (VI))
35 parts by mass of dicyclopentanyl diacrylate, 65 parts by mass of pentaerythritol tetraacrylate, and 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator are mixed to form a liquid curable resin composition ( VI) was obtained. The composition of the obtained curable resin composition (VI) is shown in Table 1.

(Preparation Example 7: Curable resin composition (VII))
Pentaerythritol tetraacrylate: 25 parts by mass, bisphenol fluorene acrylate: 40 parts by mass, and 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator: 2.5 parts by mass are mixed to obtain a liquid curable resin composition (VII). Got. The composition of the resulting curable resin composition (VII) is shown in Table 1.

(Preparation Example 8: Curable resin composition (VIII))
Cage-type silsesquioxane resin (I) obtained in Synthesis Example 1: 5 parts by weight, dicyclopentanyl diacrylate: 40 parts by weight, pentaerythritol tetraacrylate: 55 parts by weight, and 1-as a photopolymerization initiator Hydroxycyclohexyl phenyl ketone: 2.5 parts by mass were mixed to obtain a liquid curable resin composition (VIII). The composition of the obtained curable resin composition (VIII) is shown in Table 1.

Example 1
First, the curable resin composition (I) obtained in Preparation Example 1 was placed on a glass plate with a T glass-based glass cloth (trade name: T glass yarn (manufactured by Nittobo Co., Ltd.), refractive index 1.530, The upper surface was covered with a glass plate and sandwiched between the upper and lower surfaces with a glass plate, and a glass cloth was impregnated with the curable resin composition while applying pressure. Next, with this glass cloth impregnated material sandwiched between glass plates, an ultraviolet ray (wavelength: 365 nm) is irradiated with an integrated exposure amount of 2000 mJ / cm ² using an 80 W / cm high-pressure mercury lamp and a curable resin composition. The product was cured. Subsequently, it heated at 250 degreeC for 10 minute (s) in nitrogen atmosphere, and the mass ratio (mass of hardened | cured material: mass of glass fiber) of the hardened | cured material and glass fiber of thickness 0.1mm and 1 m < ² > is. A 46:54 glass fiber composite resin substrate was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Example 2)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 1 except that the curable resin composition (II) obtained in Preparation Example 2 was used instead of the curable resin composition (I). A glass fiber composite resin substrate having a mass ratio of cured resin composition to glass fiber (mass of cured product: mass of glass fiber) of 48:52 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Example 3)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 1 except that the curable resin composition (III) obtained in Preparation Example 3 was used instead of the curable resin composition (I). A glass fiber composite resin substrate having a mass ratio of the cured resin composition to the glass fiber (the mass of the cured product: the mass of the glass fiber) of 44:56 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Example 4)
Instead of the curable resin composition (I), the curable resin composition (IV) obtained in Preparation Example 4 was used, and instead of the T glass-based glass cloth, an E glass-based glass cloth (trade name: 2116 / AS887AW ( Asahi Kasei E-material Co., Ltd.), refractive index 1.558, thickness 96 μm)) was used in the same manner as in Example 1, and a cured product and glass of a curable resin composition per thickness of 0.1 mm and 1 m ^2. A glass fiber composite resin substrate having a mass ratio to the fiber (the mass of the cured product: the mass of the glass fiber) of 52:48 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Example 5)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 4 except that the curable resin composition (V) obtained in Preparation Example 5 was used instead of the curable resin composition (IV). A glass fiber composite resin substrate having a mass ratio of cured resin composition to glass fiber (mass of cured product: mass of glass fiber) of 48:52 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Comparative Example 1)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 1 except that the curable resin composition (VI) obtained in Preparation Example 6 was used instead of the curable resin composition (I). A glass fiber composite resin substrate having a mass ratio of cured resin composition to glass fiber (mass of cured product: mass of glass fiber) of 47:53 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Comparative Example 2)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 4 except that the curable resin composition (VII) obtained in Preparation Example 7 was used instead of the curable resin composition (I). A glass fiber composite resin substrate having a mass ratio of cured resin composition to glass fiber (mass of cured product: mass of glass fiber) of 49:51 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

(Comparative Example 3)
Curing per 0.1 mm thickness and 1 m ^{2 in the same} manner as in Example 1 except that the curable resin composition (VIII) obtained in Preparation Example 8 was used instead of the curable resin composition (I). A glass fiber composite resin substrate having a mass ratio of cured resin composition to glass fiber (mass of cured product: mass of glass fiber) of 47:53 was obtained. Table 2 shows the results of total light transmittance measurement and heat resistance evaluation for the obtained glass fiber composite resin substrate.

As is clear from the results shown in Table 2, all of the glass fiber composite resin substrates of the present invention have a total light transmittance of 90% or more, a sufficiently high glass transition temperature, and a dynamic viscoelastic modulus. The reduction rate was also maintained at 20% or less, and it was confirmed that the material had a high level of heat resistance and transparency. It was also confirmed that the thermal expansion coefficient was 15 ppm / K or less and the thermal expansion coefficient was sufficiently small. In contrast, in the conventional glass fiber composite resin substrate (Comparative Examples 1 and 2), although the total light transmittance is 90% or more, the glass transition temperature is low, the dynamic viscoelastic modulus reduction rate and the heat are reduced. It was confirmed that the expansion coefficient was inferior.

As described above, according to the present invention, it is possible to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and having a sufficiently small thermal expansion coefficient. Such a glass fiber composite resin substrate of the present invention has a high level of heat resistance that does not lower its modulus of elasticity even at high temperatures, so that it can be used in applications such as flexible displays, touch panels, solar cells, etc. As very useful.

Claims

A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,
The curable resin composition is
(A) a cage silsesquioxane resin having at least one group selected from the group consisting of (meth) acryloyl group, glycidyl group and vinyl group,
(B) The following general formulas (1) to (2):
-R 1 -CR 2 = CH 2 (1)
-CR 2 = CH 2 (2)
[In Formula (1), R 1 represents any one selected from the group consisting of an alkylene group, an alkylidene group, and —OCO— group. In Formulas (1) to (2), R 2 is independently A hydrogen atom or an alkyl group is shown. ]
An unsaturated compound other than the above cage-type silsesquioxane resin, having two or more unsaturated functional groups selected from the group consisting of the groups represented by: and (C) a curing catalyst, and (A) A glass fiber composite resin substrate, wherein the content of the cage silsesquioxane resin is 5 to 90% by mass with respect to the entire curable resin composition.
The (A) cage-type silsesquioxane resin is represented by the following general formula (3):
[R 3 SiO 3/2 ] n [R 4 SiO 3/2 ] m ·· (3)
{In Formula (3), R 3 represents an organic group having a group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, and a vinyl group, and R 4 represents a hydrogen atom, having 1 to 20 carbon atoms. Any one selected from the group consisting of a hydrocarbon group, an alkoxy group having 1 to 20 carbon atoms and an alkylsiloxy group having 1 to 20 carbon atoms, wherein n and m are the following formulas (i) to (iii):
n ≧ 1 (i)
m ≧ 0 (ii)
n + m = h (iii)
[In the formula (iii), h represents an integer selected from the group consisting of 8, 10, 12, and 14. ]
In the case where n and m are each 2 or more, R 3 and R 4 may be the same or different. }
The glass fiber composite resin substrate according to claim 1, which is a cage silsesquioxane resin represented by:
The glass fiber composite resin substrate according to claim 2, wherein the ratio of n to m (n: m) in the general formula (3) is 10: 0 to 4: 6.
The glass according to claim 2 or 3, wherein the cage-type silsesquioxane resin represented by the general formula (3) is 50% by mass or more based on the whole (A) the cage-type silsesquioxane resin. Fiber composite resin substrate.
The unsaturated functional group of the (B) unsaturated compound is at least one group selected from the group consisting of acryloyl group, methacryloyl group, allyl group and vinyl group. The glass fiber composite resin substrate according to one item.
The glass fiber composite resin substrate according to any one of claims 1 to 5, wherein the number of the unsaturated functional groups of the (B) unsaturated compound is 2 to 10 per molecule of the compound.
The glass fiber composite resin substrate according to any one of claims 1 to 6, wherein the glass fiber is impregnated with the curable resin composition and then the curable resin composition is cured.
The glass fiber composite resin substrate according to claim 7, wherein a mass ratio of the cured product of the curable resin composition to the glass fiber (the mass of the cured product: the mass of the glass fiber) is 20:80 to 70:30. .
The glass fiber composite resin substrate according to any one of claims 1 to 8, which has a thickness of 0.03 to 0.5 mm.